1. Field of the Invention
The invention relates to a biomedical used ultrasound phased array apparatus, particularly to a biomedical used multiple-channel hemispherical focused ultrasound phased array apparatus.
2. Description of the Prior Art
Due to most of human brain surgery is one kind of the invasive-type surgery at present, which accompanies much of therapy risk. Especially most of human brain surgery will destroy the blood-brain barrier, and generates the symptoms such as intracerebral hemorrhage, cerebral vascular accident, infection, destruction of normal nerve fiber and other temporary symptoms, thus the noninvasive therapy is become an important consideration for the medical therapy of human brain. The above-mentioned blood-brain barrier is arranged by the endothelial cell of the brain blood capillary wall mainly, which can transport the material required by the human brain tissue from the blood to the human brain by diffusion, also can protect the human brain at the same time.
The ultrasound therapy is a complete noninvasive-type therapy. Usually the focused ultrasound system is used to focus the energy into the deep part, local part of human body. After the target tissue absorbs the energy focused by the ultrasound, the temperature of local part can raise 30° C. to 55° C. in a short time. The target tissue will be necrosed and coagulated, and the normal front tissue will not be injured. The patients do not need the medical surgery, they can be treated as the clinical case, and the cost of medical therapy can be reduced greatly.
Because of the positioning precision of the focused ultrasound system, its frequency utilization rangy is 0.5 MHz to 3.5 MHz, and its energy focusing point can be controlled in 1 mm to 2 mm. In this range, the frequency can penetrate to certain depth of tissue with very good focusing ability. Thus the cavitation effect caused by the focused ultrasound system can open the blood-brain barrier temporarily. Associating with the guiding and positioning system of the magnetic resonance imaging or the ultrasound imaging etc., the drug can be introduced to brain tissue at local area of human brain precisely, through the temporary opening of blood-brain barrier. Therefore, it is paid attention by the brain surgery, which becomes an important technology for the research of human brain surgery therapy instrument and human brain functionality.
However, due to the focusing ability of low-frequency focused ultrasound system is not reached to the ideal state yet, and the focusing efficiency of single focused ultrasound system is unable to reach to the medical therapy effectively, present ultrasound device is still unable to obtain actual medical efficiency, thus there is a great improvement space.
In the prior art, Taiwan Patent Number 00480335 named as “Method and Device for the Route of Transmission Wave of Focusing Phased Array Used in Spherical Limited Material” is reviewed. This invention relates to a method and device used in the focused ultrasound system, its wave is transmitted from a phased array to a spherical limitation object, so that it can reach to a preset focus at the same time and in the same phase, and detect the crack and structure in object non-destructively. Therefore, said invention does not provide any phase adjustment way, and does not provide the medical use, thus the prior art does not cover the invention.